Automatic circuit control switch

ABSTRACT

An automatic switch for controlling an electronic circuit responsive to movement of a conductor blade from a first, or given, position relative to a lead in the switch, closing the circuit, to a second or different position relative to said lead, opening the circuit, said switch having a thruster positioned therein adjacent the conductor, said thruster being of given normal dimensions such that it will not move the conductor out of contact with the lead but being made of a material permeable and expansion-sensitive to an ambient gas or vapor, such as Freon for expanding it beyond its said given dimensions when in said vapor. On such expansion, the thruster engages the conductor and displaces it from said lead, automatically opening the switch and thus the circuit controlled thereby until such time as said vapor evaporates from the thruster and the latter returns to its normal dimensions. The conductor thereupon automatically closes the switch and the circuit controlled thereby.

Il'l 3,634,636

United States Patent Harry M. Saragovitz, Edward J. Kelly and Herbert r atve to a lead in the switch d..m rm o .um Co e v. mm .mh

CS H m m S L m T N Tm mF CM mw Cr CD H4 A s, Mm 0h TC Ul A1 .l 4 5 the thruster and the latter returns to its normal dimensions. The conductor thereupon automatically closes the switch and the circuit controlled thereby.

3,465,109 9/l969 Williams..................... 3,441,693 4/1969 Bunn 3,470,340 9/1969 Hakka.......,..................

Blesde PATENTED mi 1 ma FIG. 2

FIG. 1

l '/f JERRY H. LVO/V AUTOMATIC CIRCUIT CONTROL SWITCH The invention described herein may be manufactured, used and licensed by or for the Government for Governmental purposes without the payment (to me) of any royalties thereon.

This invention relates to a switch for automatically controlling a circuit connected thereto; the switch parts, when in normal ambient atmosphere, automatically provide a given circuit control and when in a different atmosphere (for example, a specific vapor atmosphere, as below further described) automatically move to effect a different circuit control position until such time as the switch and circuit assembly are removed from storage in the vapor atmosphere and returned to normal ambient atmosphere.

Pursuant to the invention, an on-off"on delayed-action switch is provided having numerous practical applications, as will be apparent from the disclosure herein to those skilled in the art. A spring contact conductor blade normally holds the switch in one of two positions-for example, the closed position. A thruster actuator is positioned adjacent the spring conductor blade; the thruster, in its normal dimensions, does not affect the spring blade member. The thruster is made of a material such as a rubber compound, which will expand in a Freon atmosphere against the blade to overcome the spring force thereof and displace it and hold the switch in a secondfor example, open position. The operation of the switch of the invention between two positions is automatic and positive, obviating operational error due to ambient electronic interference or accidental mechanical or other movement of the switch parts.

The switch may be disposed in a housing having a base assembly with leads sealed therethrough. The conductor contact spring is positioned in engagement with one lead, the other, free end, of said conductor contact spring being normally disposed against a second lead. The thruster actuator is interposed in the switch housing adjacent to the conductor, for engaging the conductor andmoving it away from said second lead only when said thruster swells in an ambient vapor environment to which it is dimensionally expansion sensitive. The thruster thus swells against the contact conductor spring, displacing the latter from the second lead, opening the switch and circuit controlled thereby. The switch may, for example, be used with electronically controlled munitions, enabling the munition to become operational upon separation from a Freon environment in which it is stored, thus preventing accidental operation and detonation until removal from such atmosphere and lapse of a predeterminable period of time-for example, until air-dropped munition is on the ground, thereby eliminating the possibility of electric detonation due to RF interference or to accidental mechanical actuation of the parts for any reason.

A practical form of the invention is exemplified in the drawings wherein:

FIG. 1 is a partly broken, vertical sectional view of an automatic switch embodying the invention, showing the thruster in normal, nonexpanded state, wherein the conductor contact element closes on the switch leads, closing the switch and circuit controlled thereby,

FIG. 2 is a similar view, showing the thruster, in expanded state, the contact conductor switch element being thereby moved out of contact with a switch lead, opening the switch,

FIG. 3 is a partly fragmentary, vertical elevational view, taken on line 3-3 of FIG. 2, and

FIG. 4 is a side elevational view of an exemplary form of thruster element forming part ofthe switch of this invention.

As shown in the drawings, the device of this invention comprises a switch housing which may, for example, be of shell or other desired configuration, including a top wall 1l, sidewall 12, and bottom wall or a base I3 secured to the lower flared end 14 of the sidewall l2. Thus the switch housing is essentially sealed except for one or more apertures 15 for admission (for example, through the top wall 1l thereof) of a vapor, such as Freon, to which the thruster (below described) is dimensionally sensitive.

The thruster 20 may be any configuration suitable for carrying out the invention, a convenient form being disclosed in FIG. 3. The base or header I3 may be a dielectric glass metal or other seal 16, through which the electronic circuit control leads, for example 22 and 23, may pass into the interior of the switch housing. Header 13 may be conveniently made of metal or other material for facility of securing the same to the lower end I4 ofthe switch housing.

The base assembly 13 may, as shown, be a three-lead transistor type of header; the two through leads (22-23) may be long and bent at angles toward each other to form, as above mentioned, the two contacts of the switch, and a lead 21 may be welded or otherwise secured to the base. Contact member 19 may be of any spring material of suicient force to normally (FIG. l) close on and connect leads 22-23 and to resist and overcome any force ofthe thruster 20 in normal state and until expansion thereof (FIG. 2) as described therein.

The switch may be assembled, for example, by first assembling the contact conductor spring 19 to the base assembly (FIG. 3). Thruster 20 is then placed in the cover or housing 10 (FIG. l) adjacent the member 19 without impairing its spring action (FIG. l). Base assembly 13 is then welded or otherwise secured to the housing.

Following assembly (FIG. l) the switch is closed or in its on or (in the case of munitions used) armed position, the contacts 22, 23 being electronically connected by element I9. The switch will thereafter automatically open on admission lthereinto of a vapor atmosphere (through the apertures l5 or other valving means) as to which the thruster 20 is dimensionally sensitive, causing it to swell and expand (FIG. 3). Its expansion is restrained at the top and sidewalls l1, l2 of the housing l0 so that the lower face 26 thereof will direct maximum force against the contact spring.

The sidewalls 24 of the thruster 20 are preferably (FIG. 4) tapered downwardly and inwardly, to direct the expansion forces to cause the thruster to buckle into the shape of a cup (FIG. 2) and therefor apply the maximum force of expansion in the direction of the spring element 19. Button 25 is formed on and depends from the lower face 26 of the thruster 20 to further enhance the expanded thruster action above described. After a lapse of time, the action of the expanding actuator 20 overcomes the spring force of the member 19 and moves the latter to the FIG. 2 position-which may be defined as an off or safe" condition, wherein the circuit connected to the switch leads would be open. Following assembly, the switch and controlled electronic equipment or circuit would normally be stored or placed in an atmosphere or vapor such as will maintain the thruster 20 so expanded.

The thruster 20 may be made of a natural or synthetic rubber compound, sensitive to and swelling on exposure to the vapor, such as Freon and returning to the original (FIG. l) state as the Freon evaporates. A satisfactory rubber is the rubber compound manufactured by Ames Rubber Corp., their part No. ARX-30MB; Freon-113 is very suitable for use therewith as the vapor atmosphere to which the rubber compound is expansion sensitive.

Pursuant to the requirements of the patent statutes, I have given herein an example of the invention as it may be carried out. The invention is not limited to the use of rubber or a rubber compound for the thruster 20 but covers use of any material which is sensitive to dimensional expansion in a suitable atmosphere for that purpose and will return to its original state on being freed from that atmosphere, as described herein. Similarly, while a Freon atmosphere may be used pursuant to this invention for interaction with the thruster 20, causing the latter to expand and overcome the force of the member 19 and displacing the latter from lead 22, other ambient atmospheres, which will similarly interact with and swell the thruster, may be used.

While the present invention has been particularly set forth in terms of specific embodiments thereof, it will be evident in view of the instant disclosure, that numerous variations upon the invention may be made in view of the disclosure herein by those skilled in the art, within the true scope and purview of the invention, Accordingly, the invention is to be broadly construed and limited only by the spirit and scope of the appended claims.

l claim:

1. ln an automatic switch for controlling an electronic circuit res'ponsive to movement of a conductor in said switch from a first circuit control position relative to leads in the switch, to a second circuit control position relative to said leads, wherein said switch is packaged within a container,

a thruster positioned in said container adjacent said conductor, said thruster having given normal dimensions such that it will normally not move said conductor,

said thruster being sensitive to and expanding in an ambient vapor, and, when so expanding, automatically moving said conductor to said second` circuit control position relative to said leads in said switch,

said container having sidewalls with said thruster set in abutting relationship to said sidewalls so as to extend across one radial cross section of said container, said thruster also having a downward taper, so that, on said expansion thereof in an ambient vapor, the sidewalls and top walls of said thruster will engage the adjacent side and top of said container and will buckle, thus moving the lower face of said thruster downward and against said conductor, thereby moving the latter relative to one of said leads, i

whereby said thruster, in normal, nonexpanded state, will not displaceably engage the'conductor, but will, in an ambient expanding vapor to which it is expansion sensitive, expand and so move the conductor to said second position.

2,. in an automatic switch for controlling an electronic circuit, as set forth in claim 1, said container for said switch comprising a housing having spaced top and bottom walls, said leads and conductor being so relatively positioned in said housing that said contact conductor is normally in contact with both of said leads until said thruster is expanded in said thruster-expanding vapor, pressing against said conductor and thereby displacing the latter to said second position, out of contact with the first of said leads.

3. In an automatic switch for controlling an electronic circuit, as set forth in claim 1, said thruster being provided at the lower face thereof with a projecting button portion for engagement with the conductor on said expansion of said thruster.

4. In an automatic switch for controlling an electronic circuit, as set forth in claim l,

said means for so expanding said thruster being FREON- 5. ln an automatic switch for controlling an electronic circuit, as set forth inl claim l,

said means for so expanding said thruster member being FREON-1 13, said expansible member being made of rubber expansibly sensitive thereto.

6. In an automatic switch for controlling an electronic circuit, as set forth in claim 2,

a sidewall connecting said top and bottom walls and so spacing them apart,

said thruster being so proportioned as to be adapted to be so positioned within said housing intermediate the top wall and sidewalls thereof, and said conductor.

7. In an automatic switch for controlling an electronic circuit, as set forth in claim 2, said housing being formed substantially imperforate except for means enabling admission thereinto of said vapor, to so expand the thruster.

8. In an automatic switch for controlling an electronic circuit, as set forth in claim 2, said contact conductor being a spring member.

9. in an automatic switch for controlling an electronic circuit, as set forth in claim 2, said means for so expanding said thruster being Freon.

10. A vapor-responsive switch for controlling an electronic circuit, said switch com risin a closed cylindrical ousing having vapor admissible apertures in its upper base;

a vapor-responsive thruster, said thruster confined in abutting relationship to said apertured upper base and to the upper portion of the sidewalls of` said cylindrical housing so as to extend across one radial cross section of said housing;

an upper contact and a lower contact, said'contacts spaced apart and supported from the lower base of said housing;

a U-shaped self-biasing spring contact member having one arm set proximate the lower surface of said thruster and biasingly set in contact with said upper contact, and having its other arm securably fixed to the lower base of said housing and constituting the pole of said switch;

wherein said thruster will expand in the presence of an ambient vapor, thereby forcing said first arm of said spring contact member off said upper contact and onto said lower contact, thereby effecting a switching function.

11. The switch of claim l0 wherein said lower surface of said thruster defines a central depending portion. 

1. In an automatic switch for controlling an electronic circuit responsive to movement of a conductor in said switch from a first circuit control position relative to leads in the switch, to a second circuit control position relative to said leads, wherein said switch is packaged within a container, a thruster positioned in said container adjacent said conductor, said thruster having given normal dimensions such that it will normally not move said conductor, said thruster being sensitive to and expanding in an ambient vapor, and, when so expanding, automatically moving said conductor to said second circuit control position relative to said leads in said switch, said container having sidewalls with said thruster set in abutting relationship to said sidewalls so as to extend across one radial cross section of said container, said thruster also having a downward taper, so that, on said expansion thereof in an ambient vapor, the sidewalls and top walls of said thruster will engage the adjacent side and top of said container and will buckle, thus moving the lower face of said thruster downward and against said conductor, thereby moving the latter relative to one of said leads, whereby said thruster, in normal, nonexpanded state, will not displaceably engage the conductor, but will, in an ambient expanding vapor to which it is expansion sensitive, expand and so move the conductor to said second position.
 2. In an automatic switch for controlling an electronic circuit, as set forth in claim 1, said container for said switch comprising a housing having spaced top and bottom walls, said leads and conductor being so relatively positioned in said housing that said contact conductor is normally in contact with botH of said leads until said thruster is expanded in said thruster-expanding vapor, pressing against said conductor and thereby displacing the latter to said second position, out of contact with the first of said leads.
 3. In an automatic switch for controlling an electronic circuit, as set forth in claim 1, said thruster being provided at the lower face thereof with a projecting button portion for engagement with the conductor on said expansion of said thruster.
 4. In an automatic switch for controlling an electronic circuit, as set forth in claim 1, said means for so expanding said thruster being FREON-113.
 5. In an automatic switch for controlling an electronic circuit, as set forth in claim 1, said means for so expanding said thruster member being FREON-113, said expansible member being made of rubber expansibly sensitive thereto.
 6. In an automatic switch for controlling an electronic circuit, as set forth in claim 2, a sidewall connecting said top and bottom walls and so spacing them apart, said thruster being so proportioned as to be adapted to be so positioned within said housing intermediate the top wall and sidewalls thereof, and said conductor.
 7. In an automatic switch for controlling an electronic circuit, as set forth in claim 2, said housing being formed substantially imperforate except for means enabling admission thereinto of said vapor, to so expand the thruster.
 8. In an automatic switch for controlling an electronic circuit, as set forth in claim 2, said contact conductor being a spring member.
 9. In an automatic switch for controlling an electronic circuit, as set forth in claim 2, said means for so expanding said thruster being Freon.
 10. A vapor-responsive switch for controlling an electronic circuit, said switch comprising a closed cylindrical housing having vapor admissible apertures in its upper base; a vapor-responsive thruster, said thruster confined in abutting relationship to said apertured upper base and to the upper portion of the sidewalls of said cylindrical housing so as to extend across one radial cross section of said housing; an upper contact and a lower contact, said contacts spaced apart and supported from the lower base of said housing; a U-shaped self-biasing spring contact member having one arm set proximate the lower surface of said thruster and biasingly set in contact with said upper contact, and having its other arm securably fixed to the lower base of said housing and constituting the pole of said switch; wherein said thruster will expand in the presence of an ambient vapor, thereby forcing said first arm of said spring contact member off said upper contact and onto said lower contact, thereby effecting a switching function.
 11. The switch of claim 10 wherein said lower surface of said thruster defines a central depending portion. 